China Factury best price 30307 tapered roller bearings

Tapered roller bearings

KLT offers a wide range of tapered roller bearings in both metric and inch sizes. With low cross sections and precise contact angles, these wheel bearings are designed to accommodate axial and radial loads when mounted with proper clearance. KLT tapered roller bearing sets contain a precision-matched cup and cone that are designed to install easily and maximize bearing performance and life.

Tapered roller bearings are typically used for non-driven front or rear wheels. The bearings are generally used in pairs, and they contain one inner ring and one outer ring, matched precisely with the rollers.

Bearing designations

Metric bearings

The series designations of metric tapered roller bearings with standardized dimensions according to ISO follow one of the following principles: 
The series designations established in ISO 355:1977 comprising three symbols, a figure representing the contact angle and two letters for the diameter and width series followed by a three figure bore diameter identification (d in mm). The KLT designations are prefixed by the letter T, e.g. T2ED 045

Designations established prior to 1977 based on the system shown in fig 1, e.g. 32206.

Metric bearings with a J in the prefix follow the ABMA designation system, which is similar to the system used for inch bearings, see ANSI/ABMA Standard 19.2-1994.

Inch bearings

Inch tapered roller bearings are designated according to the ANSI/ABMA standard. 
Metric bearings that belong to the same series maintain the same relative cross section regardless of their size. This is not the case with inch bearings. All inch bearings within a series use the same cage and roller assembly but the inner and outer rings can have different sizes and designs. 
Any cone (the inner ring with cage and roller assembly) can be assembled with any cup (the outer ring) belonging to the same bearing series. For this reason the cone and cup have individual designations and can be supplied separately or as complete bearings (fig 2). The designations of the cones and cups as well as the series consist of a three to six-figure number which may be prefixed by one of the following letters or combination of letters: EL, LL, L, LM, M, HM, H, HH and EH. The prefixes characterize a bearing series from extra light to extra heavy. The basic principles of this system are described in ANSI/ABMA Standard 19.2-1994. 
The complete bearing designation consists of the cone designation followed by that of the cup, the two designations being separated by an oblique stroke. 
To shorten the complete bearing designations, abbreviations are used.

Dimensions

Metric bearings

The boundary dimensions of metric single row tapered roller bearings listed in the product tables conform to ISO 355-1977 except for those bearings having a J in the designation prefix. These conform to the ANSI/ABMA Standard 19.1-1987.

Inch bearings

The boundary dimensions of inch bearings conform to AFBMA Standard 19-1974 (ANSI B3.19-1975). ANSI/ABMA Standard 19.2-1994 has subsequently replaced this standard, but this later standard no longer includes dimensions.

Adjustment and running-in

When adjusting tapered roller bearings against each other, the bearings must be rotated, so that the rollers assume their correct position, i.e. the large end face of the rollers must be in contact with the guide flange.

Conventional tapered roller bearings normally have a relatively high friction torque during the first hours of operation, which drops to a lower level after the running-in period. During this running-in period, bearing temperature increases rapidly because of the high initial friction and falls off to an equilibrium level as the running-in phase is completed.

Misalignment

The ability of a conventional single row tapered roller bearing to accommodate angular misalignment of the inner ring with respect to the outer ring is limited to a few minutes of arc. KLT bearings have the logarithmic contact profile and can tolerate misalignments of approximately 2 to 4 minutes of arc.

These guideline values apply provided the position of the shaft and housing axes are constant. Larger misalignment is possible, depending on the load and requisite service life. For additional information, please contact the KLT application engineering service.

Cages

KLT single row tapered roller bearings are fitted with one of the following cages

a pressed window-type steel cage, roller centred, no designation suffix or suffix J1, J2 or J3 (fig 1)

an injection moulded window-type cage of glass fibre reinforced polyamide 66, roller centred, designation suffix TN9 (fig 2)

a steel pin-type cage (fig 3).

Note

Tapered roller bearings with a polyamide 66 cage can be operated at temperatures up to +120 °C. The lubricants generally used for rolling bearings do not have a detrimental effect on polyamide cage properties, with the exception of a few synthetic oils and greases with a synthetic oil base, and lubricants containing a high proportion of EP additives when used at high temperatures. 
For bearing arrangements, which are to be operated at continuously high temperatures or under arduous conditions, recommends using bearings with a pressed steel or high-temperature polymer cage. 
For detailed information about the temperature resistance and the applicability of cages, please refer to the section 

Cage materials

Sheet steel cages

The majority of pressed sheet steel cages are made from continuously hot-rolled low carbon sheet steel according to (DIN) EN 10111:1998. These lightweight cages have relatively high strength and can be surface treated to further reduce friction and wear.

Pressed cages normally used in stainless steel bearings are made from stainless steel X5CrNi18-10 according to EN 10088-1:1995.

Machined steel cages

Machined steel cages are normally made of non-alloyed structural steel of type S355GT (St 52) according to EN 10 025:1990 + A:1993. To improve sliding and wear resistance properties some machined steel cages are surface treated.

Machined steel cages are used for large-size bearings or in applications where there is a danger that season cracking, caused by a chemical reaction, may occur if a brass cage were used. Steel cages can be used at operating temperatures up to 300 ºC. They are not affected by the mineral or synthetic oil-based lubricants normally used for rolling bearings, or by the organic solvents used to clean bearings.

Sheet brass cages

Pressed sheet brass cages are used for some small and medium-sized bearings. The brass used for these cages conforms to EN 1652:1997. In applications such as compressors for refrigeration using ammonia, season cracking in sheet brass might occur, therefore machined brass or steel cages should be used instead.

Machined brass cages

Most brass cages are machined from a CW612N cast or wrought brass according to EN 1652:1997. They are unaffected by most common bearing lubricants, including synthetic oils and greases, and can be cleaned using normal organic solvents. Brass cages should not be used at temperatures in excess of 250 ºC.

Minimum load

To achieve satisfactory operation, tapered roller bearings, like all ball and roller bearings, must always be subjected to a given minimum load, particularly if they are to operate at high speeds or are subjected to high accelerations or rapid changes in the direction of load. Under such conditions, the inertia forces of the rollers and cage, and the friction in the lubricant, can have a detrimental influence on the rolling conditions in the bearing arrangement and may cause damaging sliding movements to occur between the rollers and raceways.

The requisite minimum radial load to be applied to KLT standard tapered roller bearings can be estimated from 

When starting up at low temperatures or when the lubricant is highly viscous, even greater minimum loads may be required. The weight of the components supported by the bearing, together with external forces, generally exceeds the requisite minimum load. If this is not the case, the single row tapered roller bearing must be subjected to an additional radial load, which can be achieved easily by applying preload. For additional information, refer to the section

Equivalent dynamic bearing load

Equivalent static bearing load

Determination of axial forces

When a radial load is applied to a single row tapered roller bearing, the load is transmitted from one raceway to the other at an angle to the bearing axis and an internal axial force will be induced in the bearing. This must be considered when calculating the equivalent bearing loads for bearing arrangements consisting of two single bearings and/or bearing pairs arranged in tandem.

The necessary equations are provided in table for the various bearing arrangements and load cases. The equations are only valid if the bearings are adjusted against each other to practically zero clearance, but without any preload. In the arrangements shown, bearing A is subjected to a radial load F_rA and bearing B to radial load F_rB. Values of the loads F_rA and F_rB are always considered positive even when they act in the direction opposite to that shown in the figures. The radial loads act at the pressure centres of the bearings (dimension a in the product table).

In addition an external force K_a acts on the shaft (or on the housing). Cases 1c and 2c are also valid when K_a = 0. Values of the factor Y can be found in the product table.

Specification of Tapered Roller Bearings: